# Trait frunk_core::coproduct::CoproductSubsetter

source · [−]```
pub trait CoproductSubsetter<Targets, Indices>: Sized {
type Remainder;
fn subset(self) -> Result<Targets, Self::Remainder>;
}
```

## Expand description

Trait for extracting a subset of the possible types in a coproduct.

This trait is part of the implementation of the inherent method
`Coproduct::subset`

. Please see that method for more information.

You only need to import this trait when working with generic
Coproducts of unknown type. If you have a Coproduct of known type,
then `co.subset()`

should “just work” even without the trait.

## Required Associated Types

## Required Methods

Extract a subset of the possible types in a coproduct (or get the remaining possibilities)

Please see the inherent method for more information.

The only difference between that inherent method and this trait method is the location of the type parameters. (here, they are on the trait rather than the method)